Gas discharge tube binary device



March 20, 1956 G. VANDE SANDE 2,739,235

GAS DISCHARGE TUBE BINARY DEVICE Filed March 20, 1952 2 Sheets-Sheet l FIGJ.

TYPICAL INPUT SOURCE I I 16 I 17 I I nag-J OUTPUT Fig.2.

TYPICAL. Z5 Z6 21 20 n INPUT A 27 OUTPUT B FIG.3.

TYPICAL INPUT c z 5OUR CE (5+) l (5+) 1'' '-i INVEN TOR. G, Vande Sande H15 ATTORNEY.

Man}! 20, 1956 G. VANDE SANDE 3 GAS DISCHARGE TUBE BINARY DEVICE Filed March 20, 1952 2 Sheets-Sheet 2 FICa.5.

' c4 c5 C6 B E EE 53 (5+) kB+) (5+1 54 16b I OUTPUT l I i 58 53 RESET 5s FIG. 4.

OPERATlON OF CASCADED BINARY TRKJCIER CIRCUIT STAGEfi TYPICAL I a 3 4 5 6 7 8 INP T PuLsEs AW FIRST B\NARY 3e 37 COUNTER w 5% SECOND BINARY 38 39 COUNTER 5mm: m THIRD BINARY COUNTER 5TAGE 17$;

IN VEN TOR. G, \londaiandc H15 ATTORNEY.

United States Patent GAS DISCHARGE TUBE BINARY DEVICE George Vantle Sande, Greece, N. Y., assignor to General Railway Signal Company, Rochester, N. Y.

Application March 20, 1952, Serial No. 277,610

Claims. (Cl. 250-27) This invention relates to electronic binary counting devices and more particularly to an improved binary or flip-flop trigger circuit organization employing a gas discharge tube.

Electronic binary devices are widely used for a variety of purposes as in electronic computers and various other electronic control circuit organizations. These binary devices are characterized by having two distinct and stable operating conditions. In response to an input comprising a succession of voltage variations of the same polarity, these binary devices are controlled from one to the other of their two stable conditions in response to each of the input voltage variations.

A well-known type of binary device is the Eccles-Jordan trigger circuit which comprises a pair of electron tubes interconnected so as to permit conduction in only one tube of the pair at a time. The conductive condition of the one tube serves to hold the other in a stable nonconductive condition at the same time that the nonconductive condition of such other tube is effective to hold its associated tube in a stable conducting condition. Thus, the conductive and nonconductive conditions of the two tubes is a stable condition but can be reversed with the conducting tube becoming nonconductive and vice-versa by applying an input pulse to an appropriate electrode of one of the two tubes of the binary device. lt is an object of this invention to provide a binary type trigger device comprising a single gas discharge tube having two distinct and stable operating conditions, one when the tube is conductive and the other when nonconductive, and capable of being controlled alternately between these two conditions in response to each of a succession of input voltage variations of the same polarity, all of which are applied to the same tube electrodes.

Another object of this invention is to provide a binary device using a single gas discharge tube which provides in its plate circuit, when controlled to a conductive condition, a relatively high level of plate current to thereby facilitate control of various electro-mechanical devices such as electromagnetic relays and the like.

Another object of this invention is to provide a flipllop or binary device comprising a single gas discharge tube of the type having a thermionic emitting cathode, a tube of this type commonly being referred to as a thyratron.

An additional object of this invention is to provide a flip-flop or binary device using a single gas discharge tube of the grid-glow type utilizing a cold cathode.

Still another object of this invention is to provide a plurality of single-tube electronic or binary flip-flop devices cascaded so that each is controlled by the one ahead with the first of such devices receiving its input from a source of distinctive voltage variations of the same polarity so that the permutation of distinctive conditions for the plurality of binary devices is different for each number of such voltage variations to thereby provide an indication as to the number of such voltage variations which have occurred.

I of Fig. 1;

Fig. 3 illustrates a plurality of binary devices cascaded so that each is controlled by the stage ahead and with the first of such stages receiving an input of pulses from an external source;

Fig. 4 diagrammatically shows how a plurality of cascaded binary devices such as illustrated in Fig. 3 assume different combinations of conditions for diiterent numbers or input pulses; and

Fig. 5 illustrates a plurality of cascaded binary devices each of which comprises a cold cathode grid-glow tube.

To simplify the illustration and facilitate the explanation, the various parts and circuits constituting the embodiment of this invention have been shown diagrammatically, and certain conventional illustrations have been used to make it easy to understand the principles and manner of operation rather than to illustrate the specific construction and arrangement of parts that would be used in practice. The various relays and their contacts are illustrated in u conventional manner. Symbols are used to indicate connections to the terminals of batteries or other sources of electric current instead of showing all the wiring connection to these terminals. For example, the symbols (8+) and (B-) indicate connections to the opposite terminals of a source of suitably high voltage such as is required for the operation of the various electron tubes which are used. The symbol for ground" indicates a connection to a tap on the voltage source which is intermediate between the (B+) and (B) terminals. The symbols and indicate connections to the opposite terminals of a source of lower voltage such as is required for the operation of various relays and the like.

Stated briefly and without attempting to describe the scope of this invention in detail, it is proposed to provide a flip-flop or binary device using a single gas discharge tube. The input to the binary device comprises a waveform having relatively steep negative-going voltage variations. These input voltage variations are intended to be applied through separate capacitors to both the plate and cathode circuits of the gas discharge tube so that a relatively sharp negative pulse appears at the cathode of the gas discharge tube and a negative pulse of somewhat longer duration appears at the plate. if the tube is initially nonconductive, an input pulse causing negative pulses to appear in both plate and cathode circuits causes the tube to become conductive. Having once been controlled to a conductive condition, the tube remains in this state because grid control of a gas discharge tube is ordinarily lost once the tube becomes conductive. When the tube is conductive, the occurrence of a negative input pulse which is applied to both the plate and cathode circuits causes the tube to become nonconductive. Upon becoming nonconductive, the gas discharge tube remains nonconductive because of the continually applied negative grid-cathode voltage which is of suiricient magnitude to maintain the tube in a nonconductive condition until the next occurrence of a negative-going input pulse again makes it conductive.

When a plurality of the binary or flip-flop devices of ,this invention are connected in cascade, so that each device-after the first receives an input from the preceding the other in response to each second change of state of the previous stage from which it receivesits input. Thus,

each binary stage may beconsidered as a frequency divider in that it produces operation of the binary stage which it drives at a rate equal to one half of its own rate of operation. Consequently, a binary counter com-' prising n stages is capable of assuming'Za different permutations'ot' conditions for the various stages in response to a succession of inputs applied to the first binary stage. According to the present invention, it is proposed that a binary counter be provided in which each stage comprises a single gas discharge tube, either of the thermionic emitting type or of the grid-glow cold cathode type.

Thyratron binary device variations comprises a circuit organization including the voltage dividing resistors 1-6 and 15 connected between (8+) ground and the push-button contact 16. When the push-button contact 16 is open, a positive voltage appears on wire 17, but this voltage drops abruptly to ground level when the junction of resistors 14 and 15 is connected to ground by closing the push-button contact 16. it should be understood that various types of input waveforms can be applied to this electronic binary device, provided only that such input includes relatively steep sloped negative-going voltage variations which are effective, upon differentiation, to provide the required negative trigger pulses at the plate and cathode of the tube 13'. The negative-going voltage variations may, of course, occur at random; a uniform repetition rate is in no Way necessary.

The input voltage is applied through a capacitor 18 to the cathode of tube ltland through another capacitor 19 to the junction of resistors 12 and 13. As will later be more fully described, the time constant for the charging and discharging capacitor 19 is chosen to be longer than the time constant for the charging and discharging of capacitor 12 When the tube id is nonconductive, the control grid is at a suit. ble negative voltage with respect to the cathode by being connected to the junction of the voltage divider resistors 2i) and 2-1 which are connected from (B--) to ground. Alternatively, the cathode may be connected through an appropriate resistor to (13+) so that this additional r sistor along with the cathode resistor form a voltage divider effective to place a positive voltage upon the cathode, thereby providing a grid-cathode voltage that is below the firing potential of the tube.

The more detailed description of the binary device of this invention that follows ncludes one possible theory of operation of this device. it it is assumed that the gas discharge tube it? is originally nonconductive, the cathode is at ground potential and the plate is at about the potential of the (3+) voltage supply. With the push-button contact 16 open, the voltage on wire 17 is at a positive l vel above ground. The capacitor 19 is then charged to the relatively high voltage that exists between the value of the (3+) voltage supply and wire 17. The capacitor 13, onthe other hand, is charged to the lower potential difference that exists between the grounded cathode and wire 17. The negative-going voltage variation that occurs on wire 17 when the pushbutton contact 16 is closed causes capacitor 18 to discharge and thereby reduces the voltage on the cathode abruptly to a value below ground. At the same time,

the'potential difference between wire 17 and the (13+) voltage source is increased so that the capacitor 19 tends to 'charge'through resistor '13 with a resulting decrease of voltage at the junction of resistors 12 and 13 and also on the plate of tube 19. Thus, both plate and cathode voltages of tube 1% are initially caused to fall together and by substantially the same amount with the result that the plate-cathode voltage is not appreciably affected. c

The value of resistance for the cathode resistor 11 is chosen to be of a relatively low value so that the discharging of capacitor 13 occurs quickly and causes the negative voltagepulse "on the cathode of tube it) to be of short duration The charging of capacitor 19 is at a much slower rate because of the relatively high resistance of the resistor'13; Consequently, during the time that the cathode voltage is abruptly lowered and is then again increased as the discharge current through resistor 11 diminishes, the plate voltage is held at a depressed voltage by the longer enduring plate pulse.

The negative cathode pulse occurring when tube 10 isnonconduc'tive results in a less negative grid-cathode voltage. The amplitude of this negative cathode pulse is made 'sufiicient to raise the grid-cathode voltage of tube it) above theiiring potential of the tube. Also, by properly selecting the discharge rate of capacitor 13,

the duration of this negative pulse is made efiective to maintain the grid-cathode voltage above the firing potential of the tube for a long enough time to allow ionization of the gas particles tooccur so that the tube becomes and remains conductive.

Until the tube 10 becomes conductive in response to the negative'pulse applied to its cathode, the charging of capacitor 19 through the plate resistor 13 proceeds maintained at a lowered value for some time.

slowly as already set forth, so that the plate voltage is As soon as tube 10 becomes conductive, capacitor 19 discharges at a more rapid rate through a circuit path including resistor 12, the plate-cathode circuit of tube 1.0 and the cathode resistor 11. However, even at this more rapid rate, capacitor 19 is caused to discharge more slowly than capacitor 13 so that the negative-going pulse on the plate of tube 10 is of longer duration than the negativegoing pulse applied to the cathode. Thus, when tube it becomes conductive, the slow charging of capacitor 19 ceases and this capacitor then more quickly discharges until the voltage at the junction of resistors 12 and 13 has decreased to a lower level. The value of this lower voltage levelisdetermined by the drop in voltage across pulses appear at both plate and cathode of tube iii.

The grid-cathode voltage becomes .mornentarily more negative, therefore, but this is not effective in making tube it) non'conductive because the grid exerts no control when the tube is in a conductive condition.

'Also, since the time constant for the charging and discharging of capacitor 19 is chosen to be longer than the time constant for the charging and discharging of capacitor 18, forreasons presently to be described, the voltage at the cathode decreases more rapidly towards its normal value than does the voltage at the junction of resistors I123 The result is a momentary increase in platecathode voltage, and this, of course, is also ineffective to control tube iii to a nonconductive condition.

It can thus be seen that positive-going voltage variations, although characterized by a rapid rate of change so that positive voltage pulses appear on both plate and cathode of tube 10, are not able to control this tube from a conductive to a nonconductive condition.

Assuming now that tube 1 is still in a conductive condition, closure of the push-button contact 16 again produces a negative-going voltage variation on wire 17 by abruptly lowering the voltage level on wire 17 to ground. Both capacitors 18 and 19 charge so that negative-going pulses appear on both plate and cathode of tube simultaneously.

With tube It) now in a conductive condition, there is a substantial voltage drop through the plate resistors 12 and 13 so that the plate-cathode voltage of the tube is very low. In a gas discharge tube the value of this voltage that appears between the plate and cathode and which is effective to maintain the tube ionized is approximately of the order of 15 volts. The simultaneously occurring negative pulses on both plate and cathode again cause the plate and cathode voltages to initially be decreased together so that there is but little effect upon the resulting plate-cathode potential at this instant and the tube remains conductive.

The negative-going voltage pulse appearing at the plate of tube 10 is required to be of somewhat longer duration than the negative pulse appearing at the cathode. This longer duration for the plate pulse is obtained by properly selecting values of the circuit components so that the time constant for the charging and discharging of capacitor 19' is longer than the time constant for the charging and discharging of capacitor 18. Consequently, the cathode voltage rises more quickly towards its steadystate value subsequent to the negative leading edges of cathode and plate pulses than does the plate voltage. The cathode voltage thus tends to overtake the plate voltage with a resulting decrease of plate-cathode potential until finally the plate-cathode potential is no longer high enough to maintain the tube in a conductive state. The plate pulse is required to be of long enough duration with respect to the cathode pulse to maintain this condition, i. e. a plate-cathode voltage too low to maintain conduction, for a sufficient length of time to result in deionization of the tube. Thus, the tube becomes extinguished and stays in this condition because the cathode voltage i now sufiiciently high to result in a grid-cathode voltage that is below the firing level for the tube with the result that the control grid regains control of the tube.

Experiments have shown that some decoupling must be provided between the plate and cathode circuits of the tube 19. If this decoupling is not provided, a negative input applied to the tube when nonconductive causes the tube to become conductive but only momentarily, the

tube actually alternating between conducting and nonconducting conditions in an oscillatory manner. One possible reason for this behaviour is that the presence of a slight amount of inductance in the various wires and connections tends to cause the plate voltage to momentarily be depressed to a value below that required to maintain conduction when the tube initially becomes conductive and the plate voltage is abruptly lowered. When this effect causes the tube to be extinguished, the plate voltage quickly rises and again causes the tube to become conductive so that the tube alternates between conductive and nonconductive conditions for a time somewhat in the manner of a relaxation oscillator. For this reason, the resistor 12 is shown connected in the plate circuit of the tube in series with the load resistor 13 to provide the required decoupling. It is believed that the presence of this resistor in the circuit between plate and cathode of the tube tends to reduce sufficiently the Q of any inductance that might be present so as to prevent the tube from immediately extinguishing itself upon becoming conductive. Although this resistor 12 is shown connected directly in series with the plate of tube 10 and the load resistor 13, it may alternatively be connected in the circuit path leading from the junction of resistor 13 and capacitor 19, through capacitor 19 to the cathode of tube 10.

Fig. 2 illustrates a typical waveform of input and output voltages for the flip-flop or binary device of this invention. Each negative-going variation in the input voltage produces the desired negative-going voltage pulses at both plate and cathode and is thus effective to reverse the conductive state of the tube. If the tube is normally nonconductive, as represented by a high level of line B representing the output voltage of the tube, the occurrence of a negative-going voltage variation in the input voltage waveform. as shown at 25 of line A causes the tube to become conductive with a resulting decrease of plate potential as indicated by the decrease to a lower level of line B. The next negative-going input as indicated at 26 of line A then makes tube 10 again nonconductive as representated at 27 of line B.

When a plurality of the binary devices of this invention is to be connected in cascade so as to form a binary counter, they may be connected as shown in Fig. 3. Each of the binary devices shown in Fig. 3 is similar to the one shown in Fig. 1 with the exception that the required grid-cathode bias is here provided by connecting the cathode of each gas discharge tube to (Bl) through a resistor as represented by resistor 28 associated with tube 29. The value of this resistor 28 is properly chosen as compared to the value of the cathode resistor 30 so as to provide a sufficiently high level of cathode voltage with respect to the grounded control grid to normally maintain the gas discharge tube 29 nonconductive when once controlled to that condition. This means for providing the required negative grid-cathode voltage is shown here only to illustrate an alternative way of obtaining this bias voltage; it may equally well be accomplished by connecting the control grid to a source of negative voltage as shown in Fig. 1 for tube 19.

In addition, a relay C1 is included in the plate circuit of the gas discharge tube 29, in place of the load resistor 13 shown in Fig. 1. Similar relays C2 and C3 are re spectively included in the plate circuits of tubes 31 and 32. Where the inductance of the relay is of suflicient magnitude to affect the operation of the binary device, it may be desirable to connect a shunting capacitor across the Winding of each relay so as to neutralize the effect of this inductance. The resistor 33 in the place circuit of tube 29 provides the required decoupling, as previously mentioned, andthus the particular function of resistor 33 is the same as that provided by resistor 12 associated with tube 10 of Fig. 1. The means for providing the negativegoing input voltage variations is the same as shown in Fig. 1.

Each of the binary devices after the first receives its input from the plate of the preceding tube. Since the required negative-going input is received from the plate of such preceding tube only when the preceding tube becomes conductive, the binary counter of Fig. 3 is preferably organized so as to have the tube of each stage in a normal conductive condition to represent the initial or zero condition of the counter. Thus, the tubes are all normally conductive and the relays C1, C2 and C3 are all normally energized. The normal or zero condition of the counter wherein all tubes are conductive may be obtained by depressing the reset push-button 34 which connects the normally grounded control grids to a tap on the potentiometer 35 which is connected between (B+) and ground. The resulting increase of grid-cathode voltage is effective to make each tube conductive.

Although each tube after the first is shown in Fig. 3 as receiving its input from the plate of the preceding tube, the required negative-going voltage variation may also be obtained from the cathode when the tube becomes nonconductive. It is believed preferable, however, to employ the circuit organization of Fig. 3, one reason being that a higher amplitude of voltage variation occurs at the plate than at the cathode.

only to every fourth input from the input source.

- Fig. 4 is shown the elfect of a negative-going voltage variation as indicated at line A upon the first stage of the binary counter (see line 13). Thus, as tube 2? of the first binary counter stage becomes nonconductive, its plate voltage abruptly increases, as shown at 36 of line B. This increase of plate potential of tube 29 tends to produce corresponding increases of potential on both piate and cathode of tube 31 of the second stage, but these have substantially no efiect upon the conductive condition of such tube,' as has already been shown.

The second occurring negative-going input to the tube 2% of the first stage causes this tube to again become conductive. The resulting decrease in plate potential (see 37 of line B of Fig. 4) causes negative-going pulses to appear at both plate and cathode of tube 3 of the second binary counter stage so that this tube now assumes a nonconductive condition. Its plate voltage abruptly rises, therefore, as illustrated at 38 of line C of Fig. 4. Thethird input again causes tube 29 of the first stage to become nonconductive with no effect on tube 31.

The fourth input causes tube 29 to become conductive and the drop in plate voltage of this tube that then results causes tube 31 to become conductive. The plate voltage of this tube 31 then also is abruptly decreased as illustrated at 39 ofline C so that negative pulses appear at the plate and cathode of tube 32 of the third binary counter stage to cause this tube to assume a nonconductive condition, with a resulting increase in plate potential as shown at 40 of line D of Fig. 4. In this way the first binary counter stage including tube 29 responds to each input from the input source by being controlled to its opposite condition. The second stage including tube 31 is controlled to its opposite condition only when tube 29 of the first stage becomes conductive so that it responds only to every second negative-going input from the input source. The third stage including the tube 32 similarly responds Although only three stages are shown for the typical counter of Fig. 3, additional stages may readily be used where vdesired with each additional stage receiving an input from the one ahead in the manner shown.

Decoupling must be provided between the individual stages of the binary counter to prevent an input to one stage from causing operation of the next following stage. More specifically, the negative-going voltage pulse that appears on the'plate of tube 29 upon each closure of pushbutton contactlfia in Fig. 3- causes negative-going voltage variations to appear also on wire 41 and thus be applied to the cathode and plate circuits of tube 31 of the second stage. Since each stage of the counter is to be operated from one condition to the other only when the tube of the preceding stage becomes conductive, it is desirable that a pulse fed through in this manner not be effective to operate the following stage. For this reason, resistor 33 in the plate circuit of each tube must be selected to have the proper value with respect to the rest of the circuit components of each biii'ary stage to provide sufiicient reduction in amplitude .of the pulse that is passed on to the following stage so that the fed-through pulse cannot by itself cause operation of the'next tube from one'con- ---ofgrid-cathode bias-voltage: 213-? ziznthenormalconditionrpithebinaryicountrarf Fig. 3,

all of the gas tubes included therein. ates-coiiductive fand the various relays C1, C2, and C3 are all energized. A circuit is thus completed through the front contacts 42, Band 44 of these relays respectively to energize lamp 455 which is thus an indication of the count of zero. When the first input from the input source causes tube 29 to become nonconductive and relay C1 to be deenergized, a circuit is completed to illuminate the lamp 46 which then represents a count of one. In a similar manner, as each successive input is received the various stages of the binary counter assume different permutations of conductive and nonconductive conditions. For each of these diiferent permutations a different crircuit is completed through the various contacts of the relays so as to result in illuinina tion of a corresponding lamp which then indicates how many input counts have been applied to the counter.

Cold cathode grid-glow binary device Fig. 5 illustrates a plurality of binary devices, each of which comprises a single grid-glow tube of the cold cathode type. These binary devices may also be used singly, of course, instead of being cascade connected as shown in Fig. 5. Gas discharge tubes of the cold cathode, grid-glow type are characterized by the requirement that a glow discharge is initiated by causing the control grid to assume a voltage level that is substantially above that of the cathode. In other words, if the tube is initially nonconductive, the tube will not become conductive when the control grid is at the potential of the cathode, but the control grid must be driven sufiiciently positive with respect to the cathode to cause firing of the tube to occur. As with other gas discharge tubes, the grid loses control once the tube becomes conductive and the tube can thenbecome extinguished either by opening the plate cathode circuit or by reducing the plate-cathode potential below the level required to maintain reduction for a long enough time to cause deionization.

Since the grid-glow discharge tube included in each binary stageof the counter of Fig. 5 can be controlled to a conductive condition only by causing the grid to assume a more positive potential than the cathode, there is no need to provide a biasing potential in the grid-cathode circuit. More specifically, tube 59 of the first stage, for example, has its cathode connected through resistor 57 to ground and its control grid is also connected to ground through normally closed contact 55 of push-button 56.

When tube 50 is nonconductive, there is no current through the cathode resistor 51 so that both cathode and grid are at ground potential, and the tube remains nonconductive. Negative-going input voltage variations obtained by closure of push-button contact 16b are applied through separate capacitors 52 and 53 to the cathode and to the junction of resistor 54 and the winding of relay C 5 respectively. The resistor 54 is included in the circuit between plate and cathode to provide the required decoupling and .thus prevent the oscillatory variation between conductive and nonconductive conditions which might otherwise occurwhen a tube is controlled to a conductive condition and also to provide the required decoupling between successive stages as already described. v 7

It will be assumed that each of the tubes included in the counter of Fig. 5 is initially in a conductive condition. This condition may be obtained by momentarily connecting the normally grounded control grid of each tube through contact 55 of the reset push-button 56 to a positive voltage source as represented bythe potentiometer 57 connected between (3+) and ground. With the tubesSti, 53, and 59in conductive conditions, the

first occurrence of a negative-going input from the pulse source causes capacitor 53 to charge and capacitor 52 to discharge so that negative-going voltage pulses ap- "pear at both" plate and cathode of tube 5!). The time "'constantfor the charging and discharging of. capacitor 153 is selected so"as" to"be *lon'gr' thaii'the timb constant for charging and discharging of capacttor sz so. that the 9 negative-going pulse appearing at the plate of tube 50 is of greater width than the pulse appearing at the cathode.

A theory as to the manner in which tube 50 becomes nonconductive in response to these negative plate and cathode pulses is believed to be the same as that described in connection with the binary device of Fig. 1. Thus, both plate and cathode voltages initially decrease together upon simultaneous occurrence of the leading edges of the negative pulses so that the plate-cathode voltage that then results is substantially uneifected. The short cathode pulse allows the cathode voltage to rise more quickly than the voltage at the plate which is held depressed by the longer negative plate pulse. Consequently, the plate-cathode voltage finally assumes a value less than that required to maintain conduction and this condition persists for a long enough time to result in deionization of the tube. The tube thus becomes extinguished and stays in this condition because the gridcathode voltage is then not sufiiciently positive to cause the tube to again be fired.

Where a plurality of binary devices each employing a cold cathode grid-glow tube are used to comprise a binary counter, they may be cascaded as shown in Fig. Where each counter stage receives an input from the plate of the tube ahead. When the tube 50 of the first stage becomes nonconductive in response to the first negative-going input, an increase of voltage occurs at the plate of tube 50 which thus tends to produce an increase of voltage at both plate and cathode of tube 58 at the second stage. These voltage increases have substantially no effect upon the conduction of tube 58.

Upon the occurrence of the second negative-going input from the input source caused by a second closure of push-button contact 56, negative-going pulses appear at both plate and cathode of tube 50 again. Initially both plate and cathode voltages are decreased together so that there is but little effect upon the plate-cathode voltage. The decrease of cathode voltage results in an increase of the grid-cathode voltage. The amplitude of the negative cathode pulse is sufiicient to result in a gridcathode potential above the firing level for this gridglow tube, and the duration of this pulse is sufiicient to maintain the grid-cathode potential above the firing level for a long enough time to cause ionization of the tube. The tube is thus controlled to a conductive condition and maintains this condition because the grid loses control after firing of the tube occurs.

Each of the binary stages of the counter of Fig. 5 operate in a similar manner, being controlled from one condition to the other each time that the tube of the preceding stage becomes conductive in response to the second negative-going input and again becomes conductive when the fourth negative going input causes tube 50 to become conductive again.

The relays C4, C5, and C6 associated with the tubes of the counter of Fig. 5 may have their contacts included in a circuit organization similar to that provided for the counter of Fig. 3 so as to give a visual indication of the number of inputs that have been counted.

With regard to this description of a gas discharge tube binary device as a specific embodiment of this invention, it is desired to be understood that this form is selected to facilitate in the disclosure of this invention rather than to limit the number of forms that it may assume; and that further modifications, adaptations, and alternations may be applied to the specific form shown to meet the requirements of practice without in any manner departing from the spirit or scope of this invention.

What I claim is:

1. An electronic binary device including a single gas discharge tube having plate, control grid, and cathode electrodes, a plate-cathode potential source for said tube, a grid-cathode potential source for said tube to maintain said tube in a nonconductive condition when said tube is controlled to such nonconductive condition, circuit means for simultaneously applying negative-going voltage pulses to said plate and to said cathode with said pulse applied to said plate being caused to be of longer duration than said pulse applied to said cathode to provide thereby when said tube is conductive a momentary plate-cathode voltage resulting in the extinguishing of said tube, each of said pulses applied when said tube is nonconductive providing a momentary grid-cathode voltage resulting in the firing of said tube, whereby said tube is controlled alternately between stable conductive and nonconductive conditions in response to each of a succession of said pulses.

2. An electronic binary device including a single gas discharge tube of the thermionic emitting type having plate, control grid, and cathode electrodes, a plate-cathode potential source for said tube, circuit means for applying a grid-cathode potential more negative than the firing voltage for said tube, circuit means for simultaneously applying negative-going voltage pulses to said plate and cathode with said pulse applied to said plate being caused to be of longer duration than said pulse applied to said cathode to provide thereby when said tube is conductive a momentary plate-cathode voltage resulting in the extinguishing of said tube, each of said pulses applied when said tube is nonconductive providing a momentary grid-cathode voltage resulting in the firing of said tube, whereby said tube is controlled alternately between stable conductive and nonconductive conditions in response to each of a succession of said pulses.

3. An electronic binary device including a single gas discharge tube of the cold cathode grid-glow type having plate, control grid, and cathode electrodes, a platecathode potential source for said tube, a control gridcathode circuit for maintaining said tube nonconductive when once controlled to such condition, circuit means for simultaneously applying negative-going voltage pulses to said plate and said cathode with said pulse applied to said plate being caused to be of longer duration than said pulse applied to said cathode to provide thereby when said tube is conductive a momentary platecathode voltage resulting in the extinguishing of said tube, each of said pulses applied when said tube is nonconductive providing a momentary grid-cathode voltage resulting in the firing of said tube, whereby said tube is controlled alternately between stable conductive and nonconductive conditions in response to each of a succession of said pulses.

4. An electronic binary device comprising a gas discharge tube having a plate, cathode, and control grid electrodes, a plate-cathode potential source for said tube, a grid-cathode potential source to maintain said tube in a nonconductive condition upon being controlled to such nonconductive condition, circuit means for applying negative-going voltage pulses simultaneously to said plate and to said cathode, said voltage pulses applied to said cathode being of sufficient amplitude to raise the gridcathode potential momentarily above the firing potential of said tube, said pulse applied to said plate being caused to be of sutficiently longer duration than said pulse applied to said cathode to cause the plate-cathode voltage of said tube when conductive to be reduced below the value required to maintain said tube conductive for a sulficiently long interval to cause deionization of the gas within said tube.

5. An electronic binary device comprising a gas dis charge tube having plate, cathode, and control grid electrodes, a plate-cathode potential source for said tube, first coupling circuit means for applying an input voltage to said plate of said tube, second coupling circuit means for applying an input voltage to the cathode of said tube, input circuit means for applying negative-going voltage variations having a sharp rate of change simultaneously pling' circuit means and said second coupling circuit means being respectively efiective to produce negativegoin'g voltage pulses onsaid plate and said'cathode with said pulse on said plate being caused to be of longer duration than said negative-going pulse produced on said cathode, said plate and cathode pulses together providing a morne'ntary'grid-cathode voltage when said tube is nonconductive resulting in the firing of said tube, said plate and cathode pulses together providing a momentary plate-cathode voltage when saidtube is conductive resulting in the extinguishing of said tube.

6. An electronic pulse counting binary device comprising, a single gas discharge tube of the thermionic emis sion type having plate, cathode and control grid electrodes, a plate-cathode potential source, grid-cathode biasing circuit means for controlling said tube to a normally nonconductive condition, a source of negative-going voltage variations, first input circuit means for applying said voltage variations to said plate of said tube, second input circuit means for applying said voltage variations to said cathode of said tube, said first and second input circuit means being respectively effective in response to said voltage variations to produce negative-going voltage pulses at said plate and said cathode of said tube with said pulse at said plate being caused to be of longer duration relative to said pulse at said cathode, said plate and cathode pulses together providing a momentary gridcathode voltage when said tube is nonconductive resulting in the firing of said tube, said plate and cathode pulses together providing a momentary plate-cathode voltage when said tube is conductive resulting in the extinguishing of said tube, whereby said gas tube is controlled alternately between stable conducting and nonconducting conditions in response to successive occurrences of said pulses.

7. An electronic binary device comprising a gas discharge tube of the thermionic emitting type having plate, cathode, and control grid electrodes, a plate-cathode voltage source, an input wire for said device, first circuit means including a first coupling capacitor connecting said Wire to the plate circuit of said tube, second circuit means including a second coupling capacitor connecting said wire to the cathode circuit of said tube, circuit means for producing negative-going voltage variations on said Wire, said second circuit means being effective to produce a negative-going voltage pulse on said cathode in response to each of said voltage variations, said first circuit means being effective to produce a negative-going voltage pulse on said plate in response to each of said voltage variations of longer duration relative to said pulse applied to said cathode, biasing circuit means for producing a grid-cathode voltage more negative than the firing voltage of said tube.

8. An electronic binary device comprising, a gas disincluding a resistance-to provide decoupling between :-plate and said cathode.

charge tube having plate, cathode, and control grid electrodes, a plate-cathode potential source, an input source for said tubes providing negative-going voltage variations having a sharp rate of change, a load resistor included in the plate circuit of said tube, a cathode resistor connected in the cathode circuit of said tube, first input circuit means for applying said voltage variations to the plate of said tube, second input circuit means for applying said voltage variations to the cathode of said tube, said first and second input circuit means acting to produce negativegoing pulses at said plate of longer duration than the negative-going pulses produced at the cathode of said tube, said plate and cathode pulses together providing a momentary grid-cathode voltage when said tube is nonconductive resulting in the firing of said tube, said plate and cathode pulses together providing a momentary platecathode voltage when said tube is conductive'resulting in the extinguishing of said tube, said first input circuit means said 9. In an electronic binary device, a gas discharge tube having plate, cathode, and control grid electrodes, a platecathode potential-source, a cathode resistor included in the cathode circuit of said tube, a plate circuit for said tube including a load resistor and a decoupling resistor with said decoupling resistor connected directly to said plate electrode, an input source providing negative-going voltage variations haying a sharp rate of change to an input wire, said wire'being connected to said cathode and to the junction of said load and decoupling resistors through respective input capacitors, said input capacitor connecting said input Wire to said plate having a longer time constant for charging and discharging when said tube is conductive than the time constant for the charging and discharging of said input capacitor connecting said input wire to said cathode.

10. In an electronic binary device, a cold cathode grid-glow tube, a plate-cathode potentional source, an input source providing negative-going voltage variations having a sharp rate of change, first input circuit means connecting said input source to the plate of said tube, second input circuit means connecting said input source to the cathode of said tube, said first and second input circuit means being effective to produce negative-going voltage pulses at said plate and said cathode of said tube respectively in response to each of said voltage variations of said input source with said pulse at said plate being of longer duration than said pulse appearing at said cathode of said tube, whereby said tube is operated alternately between stable conductive and nonconductive conditions in response to successive occurrences of voltage variations.

11. An electronic binary device comprising, a cold cathode grip-glow gas discharge tube having plate, cathode, and control grid electrodes, a plate-cathode potential source, a cathode resistor included in the cathode circuit of said tube, a plate circuit for said tube including a load resistance and a decoupling resistor with said decoupling resistor connected directly to said plate electrode, an input source providing negative-going voltage variations having a sharp rate of change to an input Wire, said Wire being connected to said cathode and to the junction of said load resistance and said decoupling resistor through respective input capacitors, said input capacitor connecting said input wire to said plate having a longer time constant for charging and discharging when said tube is conductive than the time constant for the charging and discharging of said capacitor connecting said input wire to said cathode.

12. A plurality of cascaded binary devices each comprising a gas discharge tube having plate, control grid, and cathode electrodes, a plate-cathode potentional source for each tube, input circuit means for each of said tubes effective to produce negative-going voltage pulses at both said plate and said cathode in response to each occurrence of a negative-going voltage variation applied to said circuit means with said pulse applied to said plate caused to be of longer duration than said pulse applied to said cathode, said input circuit means associated with the first of said cascaded binary devices connected to an input source effective to provide said negative-going voltage variations, said input circuit means associated with said binary devices other than the first receiving an input from the plate of the tube included in the preceding binary device, whereby said plurality of binary devices assumes a different permutation of conductive and. nonconductive conditions for said tubes in accordance with the number of occurrences of said negative-going voltage variations produced by said input source.

13. A plurality of cascaded binary devices each including a gas discharge tube having plate, cathode, and control grid electrodes, a plate-cathode potential source for each tube, an input source providing negative-going voltage variations having a high rate of change, a cathode resistor included in the cathode circuit of each tube, a load resistance and decoupling resistor included in series in the plate circuit of each tube with said decoupling resistor connected to said plate, an input wire to each tube, first and second input circuit means associated With each tube for connecting said input wire to said cathode and to the junction of said load resistance and decoupling resistor respectively, said first and second input circuit means being eifective to produce negative-going voltage pulses at said junction in response to negative-going voltage variations appearing on said wire of longer duration than the negative-going pulses produced on said cathode, said wire associated with the tube of the first of said cascaded binary devices energized by said input source, said wire associated with the tube of each of said cascaded binary devices after the first being connected to the plate electrode of the preceding tube, whereby said tube of said first binary device is operated alternately between conductive and nonconductive conditions in response to successive negative-going voltage variation produced by said input. source and each tube of each of said binary devices after the first being operated alternately between conductive and nonconductive conditions at a rate onehalr that of the tube of the preceding device.

14. A plurality of cascaded binary devices according to claim 13 wherein said load resistance comprises an electro-magnetic relay, whereby said relays assume a different permutation of conditions for each number of input voltage variations.

15. An electronic binary device comprising, a single gas discharge tube including at least grid, cathode and plate electrodes, a plate-cathode voltage source for said tube, said cathode being connected through an impedance to a negative terminal of said voltage source, said plate being connected through a different impedance to the positive terminal of said voltage source, an input source of repetitive momentary voltage pulses all of the same polarity, first circuit means for applying each of said pulses through a first capacitor to the cathode of said tube, second circuit means for applying each of said pulses simultaneously through a second capacitor to the plate of said tube, said tube thereby being alternately controlled between stable conductive and nonconductive conditions in response to each of said pulses.

References Cited in the file of this patent UNITED STATES PATENTS 2,228,278 King, Jr. Jan. 14, 1941 2,250,819 Wolf July 29, 1941 2,428,926 Bliss Oct. 14, 1947 2,489,269 Cleeton Nov. 29, 1949 2,575,516 Hagen Nov. 20, 1951 2,600,120 MacSorley June 10, 1952 2,641,522 King June 9, 1953 

